Do you know the names of your next door neighbours? And what about those who live a couple of doors further down?
How neighbourly is your street? Tell us your story
A recent survey found that nearly six out of ten people don't know their neighbours' names.
All this week on Breakfast, the BBC's David Sillito will be looking at what it means to be a good neighbour.
He started this morning, with a street party in Bristol. And here, he tells us what he found:
Talk to almost anyone and they will say we are not as neighbourly as we used to be.
But the question is whether we should be worried? Many of us aren't bothered: rising wealth has given some of us richer and more satisfying social lives than any previous generation.
But the more we treat our homes as fortified dormitories and our streets as high speed routes to the supermarket, the less we interact with those living around us.
The weakening of social ties in our neighbourhoods has been linked to anti-social behaviour, fear of crime, depression and ill health.
So what can be done about it?
Throughout this week we are looking at how people are tackling the issue for themselves.
The city of Bristol will this Summer host more than 70 street parties.
It's an initiative led by a group called Streets Alive who help neighbourhoods come together for one day in the year.
It all sounds good fun but it can be a tense and difficult process to get it sorted out. And, the streets that truly need to get together are often the ones that have the biggest problems in getting organised.
Nevertheless, a study of the outcome of the parties found that on average each person met eight new people.
When I went to a street party in the suburb of Bishopston, I was surprised not so much that people didn't know their neighbours, but at the number they'd said they'd never even seen before.
The biggest impact is on the lives of children and the elderly.
Some residents complained about having to move their cars
This is often the only day in the year in which children are allowed to play freely outside their own homes.
Many people are startled at how many young children there are in the street when they are finally allowed out in to the space adults normally reserve for cars, wheelie bins and strangers.
On the street where we filmed, Monmouth Road, pensioner Netta Milnes said her life was utterly changed by the street party.
She now baby-sits for neighbours children and once again feels connected to people around her.
There are though those who loathe the whole thing.
Some car drivers were deeply irritated by the blocked road and being compelled to park in a different street.
Others felt uncomfortable with the forced jollity, the noise and the sense that they were not a part of things.
Being isolated is bad enough, but it seems that being isolated when everyone around you is having a marvellous time can be even worse.
But perhaps the most telling effect of the parties is to show what life can be like when the street is opened up for social life - and how isolated many of us are on the other 364 days of the year.
How neighbourly is your street? We're looking for the UK's most friendly street. Tell us your story - and we might come and film you:
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Tomorrow, we meet the residents who've improvised their own traffic calming, to try to re-claim the streets from the cars.